U.S. patent application number 10/900150 was filed with the patent office on 2005-02-03 for chemical vapor deposition processing equipment for use in fabricating a semiconductor device.
Invention is credited to Bae, Do-In, Chae, Seung-Ki, Cho, Jung-Hun, Hong, Hyung-Sik, Keum, Gyeong-Su, Kim, Yong-Gab, Park, Chung-Hun.
Application Number | 20050022742 10/900150 |
Document ID | / |
Family ID | 34101744 |
Filed Date | 2005-02-03 |
United States Patent
Application |
20050022742 |
Kind Code |
A1 |
Hong, Hyung-Sik ; et
al. |
February 3, 2005 |
Chemical vapor deposition processing equipment for use in
fabricating a semiconductor device
Abstract
Chemical vapor deposition (CVD) processing equipment for use in
fabricating a semiconductor device requiring deposition of an
insulation layer or a metal layer includes a chamber having an
exhaust line in a lower central portion thereof, a heater block for
supporting a wafer to be supplied in an interior of the chamber,
the heater block having a heating plate in an interior thereof, a
support shaft for supporting the heater block, and an electrical
wire for providing an electrical connection to the heating plate.
The support shaft extends through a bottom of the chamber. The
electrical wire extends through the bottom of the chamber within
the support shaft.
Inventors: |
Hong, Hyung-Sik; (Suwon-si,
KR) ; Keum, Gyeong-Su; (Suwon-si, KR) ; Kim,
Yong-Gab; (Suwon-si, KR) ; Park, Chung-Hun;
(Suwon-si, KR) ; Bae, Do-In; (Changwon-si, KR)
; Chae, Seung-Ki; (Seoul, KR) ; Cho, Jung-Hun;
(Suwon-si, KR) |
Correspondence
Address: |
LEE & STERBA, P.C.
Suite 2000
1101 Wilson Boulevard
Arlington
VA
22209
US
|
Family ID: |
34101744 |
Appl. No.: |
10/900150 |
Filed: |
July 28, 2004 |
Current U.S.
Class: |
118/725 |
Current CPC
Class: |
H01L 21/67103 20130101;
C23C 16/4586 20130101 |
Class at
Publication: |
118/725 |
International
Class: |
C23C 016/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 29, 2003 |
KR |
2003-52178 |
Claims
What is claimed is:
1. A chemical vapor deposition (CVD) processing equipment for use
in fabricating a semiconductor device, comprising: a chamber having
an exhaust line in a lower central portion thereof; a heater block
for supporting a wafer to be supplied in an interior of the
chamber, the heater block having a heating plate in an interior
thereof; a support shaft for supporting the heater block, the
support shaft extending through a bottom of the chamber; and an
electrical wire for providing an electrical connection to the
heating plate, the electrical wire extending through the bottom of
the chamber within the support shaft.
2. The equipment as claimed in claim 1, wherein the heater block
has a flat surface.
3. The equipment as claimed in claim 1, wherein the support shaft
has a pipe shape.
4. The equipment as claimed in claim 1, wherein the support shaft
comprises at least two support shafts, the at least two support
shafts being positioned equidistant from the exhaust line at the
lower central portion of the chamber.
5. The equipment as claimed in claim 4, wherein the heating plate
comprises: a first heating plate having a circular flat surface and
being installed in a central portion of the heater block; and a
second heating plate having a ring shape, the second heating plate
surrounding the first heating plate with a predetermined gap
therebetween.
6. The equipment as claimed in claim 5, wherein the electrical wire
is a plurality of electrical wires, a first electrical wire being
electrically connected to the first heating plate and extending
through one of the at least two support shafts and a second
electrical wire being electrically connected to the second heating
plate and extended through another of the at least two support
shafts.
7. The equipment as claimed in claim 1, wherein the support shaft
comprises: a lower portion extending through the bottom of the
chamber; and an upper portion, which is supported by the bottom of
the chamber, for contacting and supporting the heater block.
8. The equipment as claimed in claim 7, wherein the upper portion
of the support shaft has a larger cross-section than the lower
portion.
9. The equipment as claimed in claim 1, wherein the heater block
comprises: a body supported by the support shaft; a sealing member
having a ring shape on an upper edge of the body; and a platen
having a flat surface on the sealing member, wherein an upper
surface of the platen contacts a lower surface of the wafer and an
edge portion of the platen extends beyond the wafer and contacts a
side part of the body to form the interior of the heater block, the
interior of the heater block being sealed.
10. The equipment as claimed in claim 9, wherein the body and the
support shaft are integrally formed.
11. The equipment as claimed in claim 9, wherein the heater block
is formed of a ceramic material.
12. The equipment as claimed in claim 1, further comprising a lift
part positioned within the chamber for raising and lowering the
wafer, the lift part including: a cylinder supported by the bottom
of the chamber; a lift pin operable to be raised or lowered by the
cylinder; and a wafer support for contacting the wafer, the wafer
support being supported by the lift pin.
13. The equipment as claimed in claim 12, wherein the lift pin is
disposed beyond an edge of the heater block.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to fabrication of a
semiconductor device. More particularly, the present invention
relates to chemical vapor deposition (CVD) processing equipment for
use in fabricating a semiconductor device, which requires a
deposition of an insulation layer or a metal layer.
[0003] 2. Description of the Related Art
[0004] A chemical vapor deposition (CVD) process, which is
frequently performed during fabrication of a semiconductor device,
deposits a desired material layer by supplying a gaseous raw
material into a chamber having a wafer in a heated state therein.
In the chamber, the gaseous raw material reacts to a surface of the
heated wafer to form the desired material layer on the surface of
the wafer.
[0005] FIGS. 1 and 2 illustrate a partial cut-away and sectional
view, respectively, of a first conventional CVD processing
equipment for use in a CVD process. FIG. 3 illustrates an enlarged
view of a region "III" of FIG. 2 showing a connection of a heater
block to an external power source.
[0006] Referring to FIGS. 1 and 2, a chamber 10 having a
predetermined size includes a showerhead 12 for supplying a gaseous
raw material to an interior of the chamber and an exhaust line 16
for guiding and exhausting the gaseous raw material supplied to the
interior of the chamber 10. The showerhead 12 is installed on an
interior upper portion of the chamber 10 and the exhaust line 16 is
provided in a lower central portion of the chamber 10. A heater
block 20, which has a flat surface, is centrally positioned in the
interior of the chamber 10 and is equipped to support a wafer W
contained in the interior of the chamber 10. The heater block 20 is
supported by a bracket 14 fixed to an internal wall of the chamber
10 to maintain a gap between the heater block 20 and inner walls,
i.e., sidewalls and a bottom wall, of the chamber 10.
[0007] A lift part 40 is provided on a side part of the heater
block 20. The lift part 40 selectively raises and lowers the wafer
W up from or down to an upper surface of the heater block 20, i.e.
a platen 26. The lift part 40 includes a cylinder 46 supported from
a bottom of the chamber 10, a lift pin 44 that is raised or lowered
by the cylinder 46, and a wafer support 42 having a shape
corresponding to a flute 26a formed on the platen 26. The wafer
support 42 is supported by the lift pin 44.
[0008] The heater block 20 will now be described in more detail
with reference to FIGS. 1 through 3. The heater block 20 includes a
receptacle shaped body 22. The body 22 is supported by the bracket
14 installed on the internal sidewall of the chamber 10 so that a
gap is maintained between the body 22 and the internal walls of the
chamber 10. A gap retaining part 24 having a ring shape is
positioned on an upper edge portion of the body 22. A platen 26
formed of a graphite material is positioned on an upper part of the
gap retaining part 24 to contact a lower surface of the wafer W,
thereby supporting the wafer W. The body 22, the gap retaining part
24 and the platen 26 are attached together by a general fastener
26b. In addition, a support body 28 formed of a quartz material is
positioned on the body 22 between the body and the platen 26. A
first heating plate 30 and a second heating plate 32, each having a
flat surface, are positioned on an upper surface of the support
body 28. An interior of the first and second heating plates is
provided with a hot wire, i.e., a wire that is capable of
generating heat when electricity flows therethrough.
[0009] In order to electrically connect an external power source to
the first and second heating plates 30, 32, first terminal sockets
34a having a projected shape are formed on the support body 28 at
positions corresponding to the first and second heating plates 30,
32. Portions of the first and second heating plates 30, 32
corresponding to the positions of the first terminal sockets 34a
have a shape into which a corresponding first terminal socket 34a
may be inserted to form an electrical connection between the first
terminal socket 34a and either the first or second heating plate
30, 32 at a position C1. The first terminal socket 34a electrically
connects to a first electrode rod 36a inserted into the support
body 28 at a position C2. The first electrode rod 36a electrically
connects to a second terminal socket 34b at a position C3. The
second terminal socket 34b electrically connects to a second
electrode rod 36b at a position C4. The second electrode rod 36b is
connected to an external power source supply part (not shown). The
second electrode rod 36b extends through the support body 28, a
sidewall of the body 22, and exits through a sidewall of the
chamber 10.
[0010] This first conventional equipment additionally includes a
purge gas supply line 38 connected to the heater block 20. The
purge gas supply line 38 prevents an influx of gaseous raw material
into a space where the first and second heating plates 30, 32 are
positioned by supplying a purge gas into the space. The purge gas
supply line 38 extends from outside the chamber 10 through a
sidewall of the chamber 10 and the body 22 of the heater block 20.
A thermocouple 39 is installed on the heater block 20 to identify a
temperature of the first and second heating plates 30, 32. The
thermocouple 39 is inserted at a given depth into a center portion
of the platen 26 through a sidewall of the chamber 10 and the
platen 26.
[0011] One defect that frequently occurs during the performance of
multiple processes of this conventional CVD equipment is that the
first and second heating plates 30, 32 become damaged. An amount of
damage to the first and second heating plates 30, 32 increases
according to the number of processes, i.e., as the number of
processes increases, the amount of damage to the first and second
heating plates 30, 32 increases. This damage is generally caused by
a defective connection between the first and second terminal
sockets 34a, 34b, which connect the external power source to the
first and second heating plates 30, 32. This defective connection
results in a defective process and increases an expense of
maintaining the equipment because the defect necessitates changing
the first and second heating plates 30, 32, which are expensive, to
correct the defective process. In addition, there is a decrease in
an operating ratio and a productivity of the equipment. Further, a
film forms on a portion of the equipment that is connected to the
first and second terminal sockets 34a, 34b. The film has an
electrical resistance and is caused by a F.sup.- gas, which is used
in a periodic cleaning procedure performed by converting NF.sub.3
gas into a plasma state. Consequently, the terminal sockets 34a,
34b, the first and second electrode rods 36a, 36b, and the first
and second heating plates 30, 32, melt due to a temperature
increase caused by the resistance due to the film.
[0012] Moreover, the platen 26 is made of a graphite material, and
thus has a defect based on an abnormal growth on the surface
thereof during a performance of continuous processes. This defect,
which may occur in a cucumber shape, i.e., a cylindrical shape
having tapered end portions, gradually increases after a wet
cleaning. This abnormal growth of a defect, such as the cucumber
shape defect, contaminates a lower surface of the wafer W. Further,
the contaminated wafer W pollutes a buffer section having a robot
chuck or a robot, or a loadlock part (not shown), in which a
loading and unloading of the wafer W is performed during a transfer
procedure. Additionally, in a procedure of mounting the wafer W in
a cassette, the pollution may react with particles on the lower
surface of the wafer W.
[0013] FIG. 4 illustrates a sectional view of a second conventional
CVD processing equipment.
[0014] In the second conventional CVD equipment shown in FIG. 4, a
chamber 50, in which a CVD process is performed, includes a
showerhead 12, which is provided on an upper portion of the chamber
50, for supplying a gaseous raw material. An exhaust line 52 is
provided through a sidewall of the chamber 50 to guide and exhaust
the gaseous raw material supplied by the showerhead 12.
[0015] A heater block 54 is installed within the chamber 50. The
heater block 54 contacts a lower surface of a wafer W, thereby
supporting the wafer W, so that the gaseous raw material supplied
by the showerhead 12 may contact the wafer W. In operation, the
heater block 54 heats the wafer W by selectively generating heat
from a first and second heating plate 64, 66, which are provided in
an interior of the heater block 54. The heater block 54 includes a
body 56 that may be integrally formed with a pipe shaped support
shaft 56a, which extends through a lower central portion of the
chamber 50. The heater block further includes a sealing member 58
positioned on an edge portion on the body 56 and a platen 60
installed on an upper side of the sealing member 58 to contact a
lower surface of the wafer W, thereby supporting the wafer W. A
support body 62 is provided between the body 56 and the platen 60,
and is supported by the body 56. The first heating plate 64 having
a flat surface and the second heating plate 66 having a ring shape
are provided on the support body 62 so that a gap is maintained
between the first heating plate 64 and the second heating plate 66.
An electrical wire 68 for electrically connecting a power source to
the first and second heating plates 64, 66 enters a lower side of
the chamber 50 through the support shaft 56a.
[0016] A purge gas supply line 72 is connected to the support shaft
56a for preventing an influx of the gaseous raw material into the
interior of the heater block 54. A thermocouple 70 for detecting a
temperature of the first and second heating plates 64, 66 is
additionally connected to the support shaft 56a.
[0017] The heater bock 54 further includes a lift part 74 for
raising and lowering the wafer W. In the lift part 74, at least
three lift pins 76 are installed to raise and lower the wafer W.
The lift pins 76 extend through the body 56, the support body 62
and the platen 60 from a lower side of the body 56 and avoid
contacting the first and second heating plates 64, 66 of the heater
block 54. The lift pins 76 contact a lower surface of the wafer W
to support the wafer W so that an upper portion of each of the lift
pins 76 projects through an upper surface of the heater block 54 to
a predetermined height. The projection of the lift pins 76 is
controlled by selectively driving a cylinder 80 installed in a
lower portion of the heater block 54.
[0018] In the second conventional CVD equipment, the electrical
wire 68 for connecting the power source to the first and second
heating plates 64, 66 extends toward a lower side of the chamber 56
through the support shaft 56a to reduce damage to the connection.
However, the support shaft 56a extends through a lower center of
the chamber 50, and the exhaust line 52 is connected through a
sidewall of the chamber 50. Such a connection of the exhaust line
52 shifts a weight distribution of the equipment away from a center
of the chamber 50 toward the exhaust line 52. This shift in weight
distribution causes the gaseous raw material supplied into the
interior of the chamber 50 to form an air stream directed to a
portion of the chamber 50 where the exhaust line 52 is connected.
This uneven flow of gaseous raw material causes a process defect in
that a thickness of a material layer deposited on the surface of
the wafer W is formed unevenly. To prevent such a deviation of
gaseous raw material in the above-described second conventional
configuration, a connection portion of the exhaust line 52 should
be adequately spaced apart from a lower portion of the heater block
54. Such positioning, however, causes a size of the chamber 50 to
be enlarged, which necessitates an increase in an amount of gaseous
raw material supplied to the chamber 50, thus lowering
productivity.
[0019] Though an influx of gaseous raw material into the interior
of the heater block 54 may be substantially prevented by the purge
gas supply line 72, there is still a possibility that some purge
gas may flow out from the interior to an upper part of the heater
block 54 at a location where the lift pins 76 extend through the
platen 60, which adversely affects the CVD process. Further, there
is a possibility of damage to the first and second heating plates
64, 66 due to the influx of gaseous raw material through the
locations where the lift pins 76 extend through the platen 60.
SUMMARY OF THE INVENTION
[0020] The present invention is therefore directed to chemical
vapor deposition (CVD) processing equipment having an improved
structure, which substantially overcomes one or more of the
problems due to the limitations and disadvantages of the related
art.
[0021] It is therefore a feature of an embodiment of the present
invention to provide CVD processing equipment for use in
fabricating a semiconductor device, in which a downward air stream
of raw material supplied into an interior of a chamber is uniformly
provided over an entire surface of a wafer. It is another feature
of an embodiment of the present invention to provide CVD processing
equipment for use in fabricating a semiconductor device including a
connection portion for electrically connecting an external power
source to heating plates provided within a heater block.
[0022] At least one of the above features and other advantages may
be provided by a CVD processing equipment for use in fabricating a
semiconductor device including a chamber having an exhaust line in
a lower central portion thereof, a heater block for supporting a
wafer to be supplied in an interior of the chamber, the heater
block having a heating plate in an interior thereof, a support
shaft for supporting the heater block, the support shaft extending
through a bottom of the chamber, and an electrical wire for
providing an electrical connection to the heating plate, the
electrical wire extending through the bottom of the chamber within
the support shaft.
[0023] The heater block may have a flat surface. The support shaft
may have a pipe shape.
[0024] The support shaft may include at least two support shafts
and the at least two support shafts may be positioned equidistant
from the exhaust line at the lower central portion of the
chamber.
[0025] The heating plate may include a first heating plate having a
circular flat surface and being installed in a central portion of
the heater block and a second heating plate having a ring shape,
the second heating plate surrounding the first heating plate with a
predetermined gap therebetween.
[0026] The electrical wire may be a plurality of electrical wires,
a first electrical wire being electrically connected to the first
heating plate and extending through one of the at least two support
shafts and a second electrical wire being electrically connected to
the second heating plate and extended through another of the at
least two support shafts.
[0027] The support shaft may include a lower portion extending
through the bottom of the chamber and an upper portion, which is
supported by the bottom of the chamber, for contacting and
supporting the heater block. The upper portion of the support shaft
may have a larger cross-section than the lower portion.
[0028] The heater block may include a body supported by the support
shaft; a sealing member having a ring shape on an upper edge of the
body; and a platen having a flat surface on the sealing member,
wherein an upper surface of the platen contacts a lower surface of
the wafer and an edge portion of the platen extends beyond the
wafer and contacts a side part of the body to form the interior of
the heater block, the interior of the heater block being
sealed.
[0029] The body and the support shaft may be integrally formed.
[0030] The heater block may be formed of a ceramic material.
[0031] The CVD processing equipment may further include a lift part
positioned within the chamber for raising and lowering the wafer,
the lift part including a cylinder supported by the bottom of the
chamber, a lift pin operable to be raised or lowered by the
cylinder, and a wafer support for contacting the wafer, the wafer
support being supported by the lift pin. The lift pin may be
disposed beyond an edge of the heater block.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] The above and other features and advantages of the present
invention will become more apparent to those of ordinary skill in
the art by describing in detail exemplary embodiments thereof with
reference to the attached drawings in which:
[0033] FIG. 1 illustrates a partial cut-away view of a first
conventional chemical vapor deposition processing equipment;
[0034] FIG. 2 illustrates a sectional view of the first
conventional chemical vapor deposition processing equipment shown
in FIG. 1 including a heater block;
[0035] FIG. 3 illustrates an enlarged view of a region "III" of
FIG. 2 showing a connection of a heater block to an external power
source;
[0036] FIG. 4 illustrates a sectional view of a second conventional
chemical vapor deposition processing equipment; and
[0037] FIG. 5 illustrates a sectional view of a chemical vapor
deposition processing equipment according to an exemplary
embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0038] Korean Patent Application No. 2003-52178, filed on Jul. 29,
2003, in the Korean Intellectual Property Office, and entitled:
"Chemical Vapor Deposition Processing Equipment for Use in
Fabricating a Semiconductor Device," is incorporated by reference
herein in its entirety.
[0039] The present invention will now be described more fully
hereinafter with reference to FIG. 5, in which an exemplary
embodiment of the invention is shown. The invention may, however,
be embodied in different forms and should not be construed as
limited to the embodiments set forth herein. Rather, these
embodiments are provided so that this disclosure will be thorough
and complete, and will fully convey the scope of the invention to
those skilled in the art. Like reference numerals refer to like
elements throughout.
[0040] FIG. 5 illustrates a sectional view of chemical vapor
deposition (CVD) processing equipment for use in fabricating a
semiconductor device according to an exemplary embodiment of the
present invention.
[0041] According to an exemplary embodiment of the present
invention and referring to FIG. 5, CVD processing equipment for use
in fabricating a semiconductor device includes a chamber 100 having
a showerhead 12 for supplying a gaseous raw material into an upper
portion of the chamber 100, and an exhaust line 102 for discharging
air and the supplied gaseous raw material from an interior of the
chamber 100 using a downward air stream. The exhaust line 102 is
formed in a lower central portion of the chamber 100.
[0042] The chamber 100 further includes at least two pipe shaped
support shafts 108 positioned along a circumference of a portion
connected to the exhaust line 102. The at least two support shafts
108 are supported by and extend through a bottom of the chamber
100. The support shafts 108 may be desirably positioned equidistant
from a center of the bottom of the chamber 100 where the exhaust
line 102 connection is provided. Each support shaft 108 may include
a lower portion and an upper portion. The lower portion of each
support shaft is inserted into and extends through the bottom of
the chamber 100 and may be raised or lowered through the bottom of
the chamber 100. The upper portion of each of the support shafts
108 may have a relatively larger cross-sectional size than the
lower portion, e.g., may extend farther out in a side direction, so
that the upper portion of each support shaft 108 may contact and be
supported by the bottom of the chamber 100 at a location adjacent
to where the lower portion of the support shaft 108 extends through
the bottom of the chamber 100.
[0043] A heater block 104 contacts and is supported by the upper
portion of each of the support shafts 108. The heater block 104
includes a heating plate, which may be a first and a second heating
plate 116, 118, in an interior thereof. In an embodiment of the
present invention, a lower part of the heater block 104, i.e., a
body 106, and the upper portion of each of the support shafts 108
may be integrally formed and have a shape extended and projected
toward a lower side of the chamber 100.
[0044] The heater block 104 will now be described in greater
detail. The heater block 104 includes a body 106 having a flat
surface. A gap is maintained between the body 106 and the bottom of
the chamber 100 by the support shafts 108. A sealing member 110, or
a gap retaining part, having a ring shape of a predetermined
thickness is positioned on an upper surface of the body 106 at an
edge portion thereof. A platen 112 is positioned on the sealing
member 110 or the gap retaining part. The platen 112 has a flat
surface formed of a ceramic material and contacts a lower surface
of a wafer W, thereby supporting the wafer W. The platen 112 has a
shape in which an edge portion thereof covers a sidewall of the
body 106. The body 106, the platen 112 and the sealing member 110
or the gap retaining part provided therebetween are attached
together using a general fastener (not shown) to maintain a sealing
state between the interior and the exterior of the heater block
104.
[0045] A support body 115 formed of a quartz material having a
predetermined thickness is positioned on a bottom portion of the
body 106 between the body 106 and the platen 112. The first and
second heating plates 116, 118 are positioned on the support body
115. The first heating plate 116 having a circular flat surface is
positioned in a central portion of the heater block 104, e.g.,
concentric with a center of the heater block 104. Accordingly, a
center of the wafer W placed at a predetermined position on the
heater block 104 may be concentric with the first heating plate 116
and the heater block 104. The second heating plate 118 having the
ring shape is positioned a predetermined distance from the first
heating plate 116 to surround the first heating plate 116 with a
gap therebetween.
[0046] To electrically connect a power source to the first and
second heating plates 116, 118, electrical wires 114 connected to
first and second heating plates 116, 118 extended through the
bottom of the chamber 100 within the support shaft 108 and are
electrically connected to an external power source supply part (not
shown). In an embodiment of the present invention where the heating
plate is divided into at least two heating plates 116, 118, the
electrical wires 114 connected to each of the heating plates extend
through the bottom of the chamber 100 within the support shafts
108. More specifically, a first electrical wire may be electrically
connected to the first heating plate and extend through one of the
support shafts and a second electrical wire may be electrically
connected to the second heating plate and extended through another
of the support shafts.
[0047] A purge gas supply line may be connected to any one of the
support shafts 108 to supply a purge gas to prevent an inflow of
gaseous raw material into the interior of the heater block 104. A
thermocouple 120 may be inserted through any one of the support
shafts 108 to check a generation heat level of the first and second
heating plates 116, 118, i.e., a temperature of the platen 112.
[0048] A lift part 130 for raising and lowering the wafer W, which
is supported by the platen 112, is positioned to a side part of the
heater block 104. The lift part 130 includes a cylinder 136
supported by a bottom of the chamber 100, a lift pin 134, which is
raised or lowered by driving the cylinder 136, and a wafer support
132 that is supported by the lift pin 134. The wafer support 132
has a shape corresponding to a flute formed on the platen 112,
similar to the configuration of the lift part 40 shown in FIG. 1 or
2, although in the present invention, the lift pin 134 is disposed
beyond an edge of the platen 112 to avoid extending through the
platen 112 or penetrating the interior of the sealed heater block
104.
[0049] CVD processing equipment according to an embodiment of the
present invention provides the following several advantages. First,
a connection of an external power source to a heating plate
provided within a heater block may be more stably provided by
connecting an electrical wire extended from the heating plate to
the external power source supply part through a support shaft.
Second, respective components may be combined with one another in a
simplified structure, thereby reducing a size of the chamber.
Third, the structure of the present invention facilitates
assembling and disassembling the equipment, thereby reducing
inconvenience and cost of repair work when such repair work becomes
necessary. Fourth, the structure of the present invention reduces
damage to the heating plate.
[0050] Exemplary embodiments of the present invention have been
disclosed herein and, although specific terms are employed, they
are used and are to be interpreted in a generic and descriptive
sense only and not for purpose of limitation. Accordingly, it will
be understood by those of ordinary skill in the art that various
changes in form and details may be made without departing from the
spirit and scope of the present invention as set forth in the
following claims.
* * * * *